basic cardiac rhythms

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Basic Cardiac Rhythms – Identification and ResponsePRESENTERS:

ELIZABETH BORGELT, MS, RN

AMY OVERMYER, BSN, RN

Objectives▪Describe the normal cardiac anatomy and

physiology and normal electrical conduction

through the heart.

▪Identify and relate waveforms to the

cardiac cycle.

Cardiac Anatomy▪2 upper chambers▪Right and left atria

▪2 lower chambers▪Right and left ventricle

▪2 Atrioventricular valves (Mitral & Tricuspid)▪Open with ventricular diastole

▪Close with ventricular systole

▪2 Semilunar Valves (Aortic & Pulmonic)▪Open with ventricular systole

▪Open with ventricular diastole

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The Cardiovascular System▪Pulmonary Circulation

▪Unoxygenated – right side of the heart

▪Systemic Circulation

▪

Oxygenated–

 left side of the heart

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Anatomy Coronary Arteries

How The Heart Works

Anatomy Coronary Arteries▪2 major vessels of the coronary circulation

▪Left main coronary artery

▪Left anterior descending and circumflex branches

▪Right main coronary artery

▪

The left and right coronary arteriesoriginate at the base of the aorta from

openings called the coronary ostia behind

the aortic valve leaflets.

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Physiology Blood Flow

Unoxygenated blood flows from inferior andsuperior vena cava

Right Atrium

Tricuspid Valve

Right Ventricle

Pulmonic Valve

Lungs

Through Pulmonary system

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Physiology Blood FlowOxygenated blood flows from the

pulmonary veinsLeft Atrium

Mitral Valve

Left Ventricle

Aortic Valve

Systemic Circulation▪Blood Flow Through The Heart

▪Cardiology Rap

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Physiology▪Cardiac cycle

▪Represents the actual time sequence between

ventricular contraction and ventricular

relaxation

▪Systole

▪Simultaneous contraction of the ventricles

▪Diastole

▪Synonymous with ventricular relaxation

▪When ventricles fill passively from the atria to

70% of blood capacity

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 ▪Heart rate (HR)

▪

Number of contractions (beats per minute)▪Normal heart rate is 60 – 100 beats per

minute (bpm)

▪Stroke volume (SV)

▪Volume of blood being pumped out of

ventricles in a single beat or contraction

▪Normal stroke volume is 60–

 130 mL

▪Cardiac output (CO)

▪Amount of blood pumped by the left ventricle

in one minute

▪Normal cardiac output is 4–

 8 L/minCardiac Output =

Stroke Volume x Heart Rate

**Our Swan boxes give us a continuous

cardiac output reading!

▪Pre-load

▪Volume and stretch of the ventricular

myocardium at the end of diastole

▪After-load

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▪Amount of pressure against which the left

ventricle must work during systole to open the

aortic valve

▪Clinically measure by systolic blood pressure

Normal Electrical Conduction

SystemSA node

Inter-nodal pathways

AV node

Bundle of his

Left & Right bundle branches

Purkinje fibers

The SA Node and the AV Node

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Electrical Conduction SystemEKG Waveforms

One complete cardiac cycle =

P, Q, R, S, (QRS complex), and T wave